Titanium Materials With PDA Coating For Biology Application

Titanium（Ti）and its alloys,because of their excellent mechanical property,biocompatibility and corrosion resistance,have been widely used as bone implants for orthopedic surgery in biomedical treatments.However,Ti is a bioinert material which makes it hard to bond with surrounding biotic environment and bone tissue.Besides,Ti implants are inclined to be infected by bacteria which leads to the implantation failure.To solve the above problems,the surface modification technology was used to improve the bioactivity and antibacterial property of Ti implants.Firstly,we made poly-dopamine（PDA）coated on the titanium surface successfully.PDA would be prepared oxidatively polymerization by dopamine in the specially environment.The results showed that the PDA coating improved the hydroxyapatite（HAP）nucleation and growth,because of the abundant brenzcatechin,amino and ketone group in PDA which was good to attract the Ca2+ and PO43-from the solution.The mouse osteoblast cells were cultured on the PDA-Ti and Ti samples.The results showed that the PDA-Ti sample was contributed to improve the cell initial adhesion,cell growth,spreading as well as the ALP expression.These results finally showed that the PDA modified Ti implants possess excellent bioactivity which can improve the HAP growth and osseoinegration.Based on the above studies,silver nanoparticles-loaded PDA was modified on the TiO₂ nanotube array on the Ti surface（Ag-PDA-TiO₂）.The TiO₂ nanotube array was synthesized through electrochemical anodization method.The Ag nanoparticles were prepared using the reduction ability to metallic ions of PDA.From the in vitro antibacterial experiment,the sample Ag-PDA-TiO₂ showed obvious and long-term antibacterial effects as ling as 14 days compared with other experimental samples without PDA coating.